Large dielectric permittivity in the paraelectric R Mn2 O5 with R=Tb, Dy, and Er
Journal
Journal of Applied Physics
Journal Volume
103
Journal Issue
8
Date Issued
2008
Author(s)
Abstract
The complex dielectric permittivities (ε′, ε″) of R Mn2 O5 (R=Tb, Dy, and Er) are measured in the temperature range of 78-328 K with frequencies ranging from 100 Hz to 1 MHz. A large real part of the dielectric constant ε′ (40-140) is observed at room temperature in all three samples studied. These values are higher than the peak value found at the ferroelectric transition of R Mn2 O5 single crystals. Our results reveal that high dielectric permittivities are related to thermally activated dipolar motions with activation energies of ∼300 meV and a relaxation frequency of ∼3× 1012 Hz. The possible relation between the high dielectric permittivity and the size effect of R ions based on the spin-phonon interaction is suggested. © 2008 American Institute of Physics.
SDGs
Type
journal article